Method

Preheat the oven to 200C/ 180C Fan/Gas 6.

Toss the squash, onion, garlic, chilli and oil together on a baking tray and roast in the oven for 30 mins until golden and tender. Cool fully.

Unroll the pastry and, with a sharp knife, cut across its width so you have a rectangle 1⁄3 of the total size. Put on a baking tray lined with baking paper. Spoon on the pesto, leaving a 2cm border all round. Top with the roasted veg.

Brush the pastry border with egg, then top with the other piece of pastry. With a fork, seal the edges of the pastry with a crimping motion. Score a diamond pattern in the the pastry with a sharp knife.

Glaze with egg and bake for 25 mins until the pastry is golden and risen.

Drizzle the balsamic glaze over the watercress and serve with the Wellington.